JPH0572830A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To improve image quality by preventing irregularities in an electrostatic latent image recorded on a photosensitive body CONSTITUTION:This electrophotographic device is provided with the photosensitive body 1, and an exposing optical system 5 emitting scanning light in response to a picture signal on the photosensitive body, to form the electrostatic latent image thereon, and has the attachment of the photosensitive body 1 and the exposing optical system 5 to the same chassis 40. Therefore, data from the exposing optical system can be faithfully recorded on the photosensitive body, without being affected by a vibration from the outside, and high image quality is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus which visualizes an electrostatic latent image formed on a photosensitive member by a scanning optical system using a laser as a light source and transfers it to paper by toner particles. ..

[0002]

2. Description of the Related Art Conventionally, an electrophotographic apparatus has mainly been a device using a dry toner, and has been put to practical use as many copying machines, laser printers, etc., and has made remarkable progress. This electrophotographic apparatus is an apparatus to which electrophotographic process technology is applied, and visualizes an electrostatic latent image formed on a photoconductor having a photosensitive layer with toner particles. The photoconductor,
The positional accuracy and vibration characteristics of the image data with respect to the exposure optical device for recording a latent image on the photoconductor have a great influence on the electrostatic latent image to be recorded.

A conventional electrophotographic apparatus will be described below with reference to the drawings. 2 is a side sectional view of a conventional electrophotographic apparatus, FIG. 3 is a side view of a conventional developing apparatus, and FIG. 4 is a perspective view of a conventional intermediate transfer member.

In FIGS. 2 to 4, reference numeral 1 denotes a photoconductor, which is a photosensitive layer such as selenium (Se) or an organic photoconductor (OPC) on the outer peripheral surface of a belt base material such as a seamless closed loop resin. Is applied in a thin film. The photoconductor 1 is supported by two photoconductor transport rollers 2 and 3 so as to form a vertical plane between the photoconductor transport rollers 2 and 3, and is driven by a drive motor (not shown). It is rotated in the direction of arrow A along.

On the peripheral surface of the belt-shaped photoreceptor 1, a charger 4, an exposure optical system 5, black (B), cyano (Y), magenta (M) and yellow ( C) developing device 6 (6B, 6Y, 6M, 6C) for each color,
An intermediate transfer body unit 7, a photoconductor cleaning device 8, and a neutralizer 9 are provided.

The charger 4 comprises a charging wire 11 made of a tungsten wire or the like, a shield plate 12 made of a metal plate, and a grid plate 13. By applying a high voltage to the charging line 11, the charging line 11 causes corona discharge, and the photoconductor 1 is uniformly charged through the grid plate 13.

Reference numeral 14 is an exposure light beam of image data emitted from the exposure optical system 5. In the case of a laser printer, the exposure light beam 14 is controlled by a signal from a host computer (not shown), and a plurality of exposure light beams 14 corresponding to specific components of a plurality of predetermined color components are provided on the photoconductor 1. To form an electrostatic latent image of.

In FIG. 3, reference numeral 6a denotes a toner carrying member of the developing device 6, which is made of a wire such as stainless steel, and has both ends bent in a rectangular shape and rotatably supported by both ends of the developing butt 6b. The toner conveying member 6a is
The toner 6c in the developing device 6 is prevented from blocking, and the toner 6c is conveyed onto the replenishing roller 6d.

The supply roller 6d has a structure in which a conductive layer such as urethane is layered on the outer peripheral surface of a metal such as stainless steel as a base material, and both ends are rotatably supported by the developing bat 6b. Then, the toner 6c transported by the toner transport member 6a is replenished to the surface of the developing roller 6e.

The developing roller 6e has a structure in which a conductive layer such as silicon or urethane is formed in layers on the outer peripheral surface of a metal such as stainless steel as a base material, and is rotatable at both ends of the developing pad 6b. The toner 6c, which is rotatably supported by the replenishing roller 6d, is charged and formed into a thin layer by the toner regulating blade 6f formed of a conductive member such as silicon or urethane, and contacts the photoconductor 1. Toner 6c is attached to the portion of the electrostatic latent image 1 on which the electrostatic latent image is formed to form a toner image.

A toner remaining amount sensor 6g detects the presence or absence of the toner 6c in the developing device 6 and outputs a replacement signal for the developing device 6. The developing device 6 for each color stores the toner 6c corresponding to each color. To select the color of the toner 6c, the separation / contact cams 15B, 15Y, 15B, and 15C, both ends of which are rotatably supported by the main body of the machine, are used as color selection signals of a host computer (not shown). Corresponding rotation is carried out by bringing the selected developing device 6B, 6Y, 6M, 6C, for example, the black developing device 6B into contact with the photoconductor 1. The remaining developing devices 6Y not selected,
6M and 6C are separated from the photoconductor 1.

The intermediate transfer member unit 7 is a seamless loop belt-shaped intermediate transfer member 1 made of a conductive resin or the like.
6 and three intermediate transfer body transport rollers 17, 18, 19 that support the intermediate transfer body 16 and rotate in the direction of arrow B.
In order to transfer the toner image on the photosensitive member 1 to the intermediate transfer member 16, the intermediate transfer member 20 is provided so as to face the photosensitive member 1 with the intermediate transfer member 16 interposed therebetween.

Reference numeral 21 denotes an intermediate transfer member reference detection sensor for detecting the reference position of the intermediate transfer member 16.
The reference position is detected by the intermediate transfer member reference mark 16a (see FIG. 4) such as a slit arranged at one end of the.

Reference numeral 22 denotes an intermediate transfer member cleaning device for scraping off the residual toner on the intermediate transfer member 16, and while the composite image is being formed on the intermediate transfer member 16, the intermediate transfer member 1 is provided.
It is separated from 6, and contacts only when it is used for cleaning.

A transfer material cassette 23 contains a transfer material 24. The transfer material 24 is sent from the transfer material cassette 23 one by one to a paper transport path 26 by a half-moon shaped paper feed roller 25.

Reference numeral 27 denotes a registration roller that temporarily stops and waits the transfer material 24 in order to match the positions of the transfer material 24 and the composite image formed on the intermediate transfer body 16, and is pressed against the driven roller 28. ..

Reference numeral 29 is a transfer roller for transferring the composite image formed on the intermediate transfer body 16 to the transfer material 24, and rotates in contact with the intermediate transfer body 16 only when the composite image is transferred to the transfer material 24. ..

Reference numeral 30 denotes a heat roller 3 having a heat source inside.
1 is a fixing device including a pressure roller 32 and a transfer material 2
The composite image transferred onto the image recording medium 4 is fixed on the transfer material 24 by pressure and heat as the heat roller 31 and the pressure roller 32 are nipped and rotated to form a color image.

Reference numeral 33 denotes a transfer material discharge roller having a metal such as stainless steel as a base material and an elastic layer such as urethane formed on the outer peripheral surface thereof. The transfer material discharge roller 33 is rotatably supported at both ends of the machine body by an arrow. The transfer material 24 on which a color image has been formed by rotational driving in the direction is discharged onto the transfer material storage member 34 with the image surface as the upper surface in order on the previously discharged transfer material.

The operation of the electrophotographic apparatus configured as described above will be described. The photosensitive member 1 and the intermediate transfer member 16 are driven by driving sources (not shown), respectively, and are controlled so that their peripheral speeds become the same constant speed. Further, the intermediate transfer member 16 has an intermediate transfer member reference detection sensor 2 for detecting an intermediate transfer member reference mark 16a for determining a reference position.
1, the image forming area is set in advance.

In this state, first, a high voltage is applied to the charging wire 11 in the charger 4 connected to the high voltage power source to cause corona discharge, and the surface of the photoconductor 1 is uniformly charged to about -700v to -800v. Let

Next, the photosensitive member 1 is rotated in the direction of arrow A, and a laser beam or the like corresponding to a predetermined black (B) of a plurality of color components is formed on the surface of the photosensitive member 1 which is uniformly charged. When the exposure light beam 14 is irradiated, the electric charge disappears in the irradiated portion on the photoconductor 1 and an electrostatic latent image is formed. At this time, the electrostatic latent image is formed at a position in the image area on the intermediate transfer body 16 which is preset by a signal from the intermediate transfer reference detection sensor 21 which detects the reference position of the intermediate transfer body 16.

On the other hand, the developing device 6B containing the black toner contributing to the development is pushed in the direction of the arrow B by the rotation of the separation / contact cam 15B in response to a color selection signal from a host computer (not shown), and the photosensitive member 1 is then moved. Abut. With this contact, toner adheres to the electrostatic latent image portion formed on the photoconductor 1 to form a toner image, and the development is completed. The developing device 6B that has completed the development is moved from the contact position with the photoconductor 1 to the separation position by the 180 ° rotation of the separation cam 15B.

The toner image formed on the photosensitive member 1 by the developing device 6B is transferred to the intermediate transfer member 16 by applying a high voltage to the intermediate transfer roller 20 arranged in contact with the photosensitive member 1 for each color. The residual toner that has not been transferred from the photoconductor 1 to the intermediate transfer member 16 is removed by the photoconductor cleaning device 8, and the residual toner is scraped off by the static eliminator 9 to remove the charges on the photoconductor 1.

Next, for example, when the color of cyan (C) is selected, the separation cam 15C is rotated, and this time the developing device 6C is pushed toward the photoconductor 1 and brought into contact with the photoconductor 01, and the cyan (C) color is selected. ) Development is started. In the case of a copying machine or printer using four colors, the above-described developing operation is sequentially repeated four times to form toner images of four colors B, C, M and Y on the intermediate transfer body 16 to form a composite image. The composite image thus formed is transferred from the transfer material cassette 23 to the paper transport path in a state where the paper transfer roller 29, which has been separated so far, comes into contact with the intermediate transfer body 16 and applies a high voltage to the paper transfer roller 29. It is collectively transferred to the transfer material 24 sent along the line 26.

Then, the transfer material 24 on which the toner image is transferred is sent to the fixing device 30, where it is fixed by the heat of the heat roller 31 and the nip pressure of the pressure roller 32, and the transfer material discharge roller 33 moves in the direction of the arrow. By the rotational driving of the transfer material 24, the transfer material 24 on which the color image has been formed is discharged onto the transfer material storage member 34 with the image surface as the upper surface, while being sequentially stacked on the transfer material previously discharged.

Residual toner on the intermediate transfer body 16 which is not completely transferred onto the transfer material 24 by the sheet transfer roller 29 is removed by the intermediate transfer body cleaning device 22. The intermediate transfer body cleaning device 22 is at a position apart from the intermediate transfer body 16 until a single composite image is obtained, and a composite image is obtained and the composite image is transferred to the transfer material 24 by the paper transfer roller 29. After that, the contact state is established and the residual toner is removed.

Image recording is completed by the above operation. Here, the exposure optical system 5, the developing devices 6B, 6Y, 6M, 6C,
The transfer roller 29, the paper feed roller 25, the fixing device 30, and the like are held and assembled by the chassis 38, while the photoconductor 1, the photoconductor cleaning device 8, the charger 4, the charge eliminator 9, the intermediate transfer member 16, and the like are provided. It is held and fixed to the chassis 39, and the photoconductor 1 can be removed from the chassis 39. And the chassis 39 is the chassis 3
It has a mechanism that can be positioned at 8. Therefore, the positioning accuracy between the chassis 38 and the chassis 39 is necessary, the relative positional accuracy between the exposure optical system 5 and the photoconductor 1 must be maintained, and the vibration between the chassis 38 and the chassis 39 causes There is a problem that the light emitted from the exposure optical system 5 is registered on the photoconductor 1 in a shifted state.

Reference numeral 36 denotes an operation panel, which is an indicator lamp 3.
7 and the like are provided.

[0030]

As described above, in the conventional configuration, the electrostatic latent image of the photoconductor 1 is disturbed by the vibration characteristics of the exposure optical system 5 and the photoconductor 1, and the image data is accurately formed. However, the image quality was significantly deteriorated.

The present invention solves the above problems, and an object of the present invention is to provide an electrophotographic apparatus in which the electrostatic latent image on the photoconductor is not disturbed even when the entire apparatus or the like vibrates. It is a thing.

[0032]

In order to solve the above problems, the present invention has an exposure optical system and a photoconductor mounted on the same chassis.

[0033]

By the above means, since the exposure optical system and the photoconductor are mounted on the same chassis, even if the entire apparatus is vibrated, the relative displacement is eliminated, and the accurate laser beam on the photoconductor is eliminated. It becomes possible to record an electrostatic latent image by.

[0034]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a side view of an electrophotographic apparatus according to an embodiment of the present invention, and the side view of a developing device and the perspective view of an intermediate transfer member are the same as those of the related art (FIGS. 3 and 4).
Omit it. Further, the same components as those in the conventional electrophotographic apparatus are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 1, the outer shape of the entire apparatus is constituted by a chassis 38 similar to the conventional one. Among them, the photoconductor 1, the charger 4, the exposure optical system 5, the intermediate transfer body unit are included. 7, the photoconductor cleaning device 8, the static eliminator 9, and the intermediate transfer member 16 are attached to a chassis 40, and the chassis 40 can be positioned on the chassis 38. Then, the transfer roller 29 and the transfer material cassette 2
3, the paper feed roller 25, and the fixing device 30 are mounted on the chassis 48 as in the conventional case. The developing devices 6B, 6Y, 6
M and 6C may be attached to either chassis 38 and 40.

According to the above construction, even if the photoconductor 1 and the exposure optical system 5 are vibrated by the vibration in the apparatus (vibration of the motor or the like) or the disturbance vibration from the outside of the apparatus, the same chassis 38 can be oscillated. In addition, since the members are connected by a member having high rigidity, the same vibration mode is achieved, the relative positional accuracy between the laser scanning light and the photosensitive member can be maintained, and the electrostatic discharge by the accurate laser light on the photosensitive member can be maintained. It becomes possible to record a latent image.

[0037]

As described above, according to the present invention, by mounting the photoconductor and the optical device in the same chassis,
Even if these are vibrated, relative displacement between the exposure optical system and the photoconductor can be prevented, so that an accurate electrostatic latent image can be formed on the photoconductor, and a high quality image can be obtained.

[Brief description of drawings]

FIG. 1 is a side view of an electrophotographic apparatus according to an embodiment of the present invention.

FIG. 2 is a side sectional view of a conventional electrophotographic apparatus.

FIG. 3 is a side view of a conventional developing device.

FIG. 4 is a perspective view of a conventional intermediate transfer member.

[Explanation of symbols]

 1 photoconductor 5 exposure optical system 40 chassis

Claims (1)

[Claims] 1. A photoconductor, and an optical device that emits scanning light according to an image signal to the photoconductor to form an electrostatic latent image on the photoconductor, and the photoconductor and the optical device. An electrophotographic device with the same chassis attached.